:root {
    --bg: #f8f8f8;
    --text: #111111;
    --text-light: #777777;
    --accent: #d3d3d3;
    --black: #000000;
    --white: #ffffff;

    --sans: 'Inter', 'Noto Sans TC', sans-serif;
    --serif: 'Playfair Display', 'Noto Serif TC', serif;

    --transition: 0.8s cubic-bezier(0.16, 1, 0.3, 1);
    --fast: 0.4s ease;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--sans);
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Background Grid */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        linear-gradient(to right, rgba(0, 0, 0, 0.03) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(0, 0, 0, 0.03) 1px, transparent 1px);
    background-size: 80px 80px;
    z-index: -1;
    pointer-events: none;
}

/* Typography Tools */
.serif {
    font-family: var(--serif);
}

.serif-italic {
    font-family: var(--serif);
    font-style: italic;
    font-weight: 400;
    color: var(--text-light);
}

.dot {
    color: var(--accent);
}

.text-white {
    color: var(--white);
}

/* Layout */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 5vw;
}

.section {
    padding: 150px 0;
}

/* Nav */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 30px 0;
    z-index: 100;
    background: linear-gradient(to bottom, rgba(248, 248, 248, 0.95) 0%, rgba(248, 248, 248, 0) 100%);
    backdrop-filter: blur(4px);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 5vw;
}

.logo {
    font-size: 1.25rem;
    font-weight: 900;
    letter-spacing: 0.1em;
}

.nav-links {
    display: flex;
    gap: 40px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    transition: var(--fast);
}

.nav-links a:hover {
    color: var(--text-light);
}

/* Marquee */
.marquee-container {
    position: absolute;
    top: 20vh;
    left: 0;
    width: 100%;
    overflow: hidden;
    white-space: nowrap;
    z-index: -1;
    opacity: 0.05;
    pointer-events: none;
}

.marquee {
    display: inline-block;
    animation: scroll 40s linear infinite;
    font-size: 10vw;
    font-weight: 900;
    letter-spacing: -0.02em;
}

@keyframes scroll {
    0% {
        transform: translateX(0);
    }

    100% {
        transform: translateX(-50%);
    }
}

/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 100px;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 5vw;
    align-items: center;
    padding: 0 5vw;
    max-width: 1600px;
    margin: 0 auto;
    width: 100%;
}

.eyebrow {
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.3em;
    margin-bottom: 2rem;
    color: var(--text-light);
}

.title-main {
    font-size: 7vw;
    line-height: 0.95;
    font-weight: 900;
    letter-spacing: -0.03em;
    margin-bottom: 2rem;
}

.subtitle {
    font-size: 1.1rem;
    max-width: 400px;
    color: var(--text-light);
    margin-bottom: 3rem;
}

.explore-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    text-decoration: none;
    color: var(--text);
    border-bottom: 1px solid var(--text);
    padding-bottom: 5px;
    transition: var(--fast);
}

.explore-btn:hover {
    padding-bottom: 10px;
    gap: 20px;
}

/* Hero Image */
.hero-visual {
    position: relative;
    height: 75vh;
}

.image-wrapper {
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.main-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(100%) contrast(1.1);
    transition: 1.5s ease;
    transform: scale(1.05);
}

.hero-visual:hover .main-img {
    filter: grayscale(0%) contrast(1);
    transform: scale(1);
}

/* Section Headers */
.section-header {
    margin-bottom: 80px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: end;
}

.section-title {
    font-size: 3rem;
    font-weight: 900;
    letter-spacing: -0.02em;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 400px;
}

/* Teaching / Cards */
.card-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2px;
    background: var(--gray-mid);
    border: 1px solid var(--gray-mid);
}

.course-card {
    background: var(--bg);
    padding: 60px;
    text-decoration: none;
    color: var(--text);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 400px;
}

.course-card:hover {
    background: var(--black);
    color: var(--white);
}

.card-top {
    display: flex;
    justify-content: space-between;
    margin-bottom: 40px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.1em;
}

.course-card:hover .card-top {
    color: var(--white);
    opacity: 0.5;
}

.course-card h3 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    font-weight: 400;
}

.card-arrow {
    position: absolute;
    bottom: 60px;
    right: 60px;
    font-size: 2rem;
    font-weight: 300;
    opacity: 0;
    transform: translateX(-20px);
    transition: var(--transition);
}

.course-card:hover .card-arrow {
    opacity: 1;
    transform: translateX(0);
}

/* Lectures */
.dark-section {
    background-color: var(--black);
    color: var(--white);
}

.timeline-row {
    display: grid;
    grid-template-columns: 300px 1fr;
    padding: 60px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
    text-decoration: none;
    color: inherit;
}

.timeline-row:first-child {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.timeline-row:hover {
    padding-left: 20px;
    background: rgba(255, 255, 255, 0.03);
}

.time-date {
    font-weight: 700;
    letter-spacing: 0.1em;
    color: var(--text-light);
}

.time-content h3 {
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 10px;
}

.time-location {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* About */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-large-text h2 {
    font-size: 5vw;
    line-height: 1;
    font-weight: 400;
}

.about-details p {
    font-size: 1.2rem;
    margin-bottom: 60px;
}

.stats-box {
    display: flex;
    gap: 60px;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-num {
    font-size: 4rem;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    color: var(--text-light);
}

/* Footer */
.footer {
    padding: 60px 0;
    border-top: 1px solid var(--gray-mid);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: end;
    padding: 0 5vw;
    max-width: 1600px;
    margin: 0 auto;
}

.footer-logo {
    font-size: 2rem;
    font-weight: 900;
    letter-spacing: -0.02em;
}

.footer-copy {
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    color: var(--text-light);
    text-align: right;
}

/* Animation Classes */
.gsap-reveal {
    opacity: 0;
    transform: translateY(60px);
    transition: 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.gsap-reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

.delay-1 {
    transition-delay: 0.2s;
}

.delay-2 {
    transition-delay: 0.4s;
}

/* Responsive */
@media (max-width: 900px) {

    .hero-grid,
    .section-header,
    .card-grid,
    .timeline-row,
    .about-grid {
        grid-template-columns: 1fr;
    }

    .hero-visual {
        height: 50vh;
        order: -1;
        margin-bottom: 40px;
    }

    .marquee-container {
        display: none;
    }

    .title-main {
        font-size: 15vw;
    }

    .nav-links {
        display: none;
    }
}